Q&A # 285 - April 28, 2002

Staff

Q I am writing about the excellent lab results provided by J. E. Johnson on the PS Audio Ultimate Outlet review. I think it is excellent that you show results like this so we can get an idea of the effects of a power device. I think that in that particular review it would also be useful if we could see (spectrum A (subtract) spectrum B) to see the overall difference vs. frequency. Also it would be nice to connect a spectrum analyzer to check for what's going on with the real (resistive) and imaginary (inductive/ capacitive) part of the impedance.

A Thank you for the support. Doing these tests requires a lot of work, so it is nice to know it is appreciated. We are in the process of adding all sorts of test equipment and software so that we can provide the type of information you requested, which involves transform functions.

Q When I look at preamplifier/amplifier brochures, I see all kinds of specs that don't necessarily correlate with the price, such as frequency response, distortion, power, etc. Which one is the most important?

A Here is my (JEJ) opinion on this. The first thing I like to know is the type of distortion the preamp or amplifier produces. Second, comes the amount of distortion. Third is the amount of power in the case of amplifiers, and fourth is the frequency response.

Here is an example. I collected some spectra on our reference Balanced Audio Technology VK-5i Class A triode preamplifier. Below are shown the frequency response curves. Notice how it falls off beginning at about 200 Hz and below (down 1 dB at 24 Hz), and about 8 kHz and above (down 0.2 dB at 20 kHz). By solid state standards, this would not be so good. But, it is typical of tube products. Now, look at the THD distortion spectrum from a 1 kHz sine wave input (third graph below). Note that the only harmonic is the second ordered one at 2 kHz (the peaks above 50 kHz are an anomaly that may or may not have anything to do with the preamp). A solid state preamp could only dream of having this kind of distortion spectrum, especially one that uses op amps at the output. This spectrum is typical of triodes and is highly sought after by tube product aficionados. But the tube frequency response chart would be laughable in a solid state product. So, we give up the frequency response smoothness in trade for a beautiful distortion spectrum. It is the odd ordered harmonics, in very low levels, that make a sound harsh. If an amplifier has a poor distortion spectrum, it won't matter about the power or frequency response it has. Of course, this is just my opinion. Others may value different characteristics. For example, touring amplifiers used by rock groups on the road have tons of watts that can be delivered into 4 Ohms, but they are noisy, and because they are digital switching, will likely not have good high frequency characteristics. There are some fine digital amplifiers out there, but they have much more expensive technology. There would be no point in using a powerful, and yet very clean, power amplifier, because the rock groups play so loud, the speakers product lots of distortion. The touring amplifiers are $600 for 1000 watts. They make good subwoofer amps though.

Q I am not an audio- or video-phile but I like nice sound and video and like to get the absolute most value for my money. I upgraded my receiver to the B&K AVR202 (which I got an awesome closeout deal on). I plan on upgrading my speakers to the B&W 804s as soon as I find a slightly used or internet buy for around $2600. I have a small place so don't plan on going to surround sound in the near future.

I need a CD player to feed into this system and figure I might as well get a DVD player instead and kill 2 birds with one stone. I just have a small Toshiba TV (RF input only, but till a nice picture) so I'm not overly concerned with Video performance, although if I can get something that will last through a TV upgrade in a year or two, I'd pay a little extra now to do so.

Given my situation, I'm thinking of going fairly low end on the DVD, a better mass market machine $225 or so. I'm not that concerned with MP3 or CD-R because I don't take the time to build my own discs anyway. I'm also not thinking DVD-A or SACD because that battle will still take a year or two to sort out and why buy one or the other to find you picked the wrong one? If I have an option for just a few more bucks I'd probably pick up SACD, as I'm more concerned about 2 channel audio performance than multi channel sound.

The question I have is, how much am I giving up on the CD side of things with a mass market DVD player? My thought is to just take the digital out of the player and use the D/A in the B&K, which should be quite good? I'm thinking that if I pay for a better CD player, mostly all I get will be better D/A, so why should I buy more when I already have it in the B&K?  Can you confirm my thought process here, am I missing anything? If you agree, can you recommend a mass market player that would have the best CD transport (if that's the right term, I'm stretching)?

A The best bet is to get a DVD player that is set up for DVD-A, because the DACs in these players have to meet much higher standards than for CD, and when you play CDs, you get the benefit of those better DACs. You might as well get a DVD player that does not have the chroma bug, and we are getting ready to test some new DVD-A players that are supposed to have eliminated the bug, so hold off your purchase for a few weeks.

Q I have finally made the decision to upgrade my television from a a 27" Mitsubishi to something more modern. But with all the new televisions, it's hard to know where to start. I am looking for some recommendations for a television between $1,000-$2,000. I currently have the following components:

Teac 8900 AV Receiver
Teac Surround Speakers and Subwoofer
Panasonic RV-30 DVD Player
Sony SLV N51- HiFI VCR

I am looking for a few choices that I can then narrow down myself. Thanks for your help.


A Yesterday, I saw a Pioneer Rear Projection HDTV (50" I think), for $2,795 at CostCo. At this point, because HDTVs are getting so inexpensive (relative to what they used to be), you should go for the digital television. It had 1080i, 480p scaling from 480i input, and progressive scan component video inputs. There is no reason to buy an NTSC TV anymore. You could connect a $159 progressive scan DVD player to this TV and have a picture that was not available for less than $8,000 just a year or two ago.

Q  I just recently bought the Kenwood HTB-504DV home system.

Two problems have arose that are very confusing and I was hoping you could shed some light on them.

First is the component connection: My DVD was connected to my Sony TV's component - and all I could get are monochrome images! The cables are high quality and I'm sure I connected the 3 cables correctly. When I tried to rearrange them, I got no images to the TV. My S-Video works just fine, and if I used just one RCA cable from one of the DVD's component out to the TV's in, I also get normal color images. Any ideas?

My second problem is just as equally confusing. I have an optical connection from my DVD player to the receiver. Everything was working fine, then one night I could not get any sound from the speakers at all - I could not even get the receiver to generate the pink noise to each speaker. I was able to get some noise from my TV through the receiver, but there was massive interference. Now out of desperation, I decided to try connecting my DVD player to the receiver with a coaxial cable that came with the system. Lo and behold, everything returned to normal working order after that!

TV, DVD (both optical and the coaxial) worked, and the receiver was able to generate the pink noise. If I unplugged the coaxial (optical still plugged in), everything went crazy again. I would be content to live with S-Video and just leaving my receiver alone with both optical and coaxial in as long as it worked, but I'm afraid there's a serious problem brewing here.

I bought the system through the internet so the prospect of having to return it/exchange it is not appealing at all.

A First, try using the three component video cables in different combinations, making sure that the jacks from the player go to the correct jacks on the TV. If this results in varying picture, then one or more of the cables is defective. If it does not change anything, then either one of the outputs of the player or one of the inputs on the TV is defective. As to your optical connection from the player to the receiver, if you have both the coaxial and optical cables connected at the same time, your receiver is probably defaulting to the coaxial input and ignoring the optical input. I suspect the optical output of the player or the optical input on the receiver has become defective. If your receiver has more than one optical input, try that option.

Q The manual for my receiver says something about component video connections mean you don't get an on-screen display (OSD). Can I use the S-Video connection and component video at the same time to see the OSD?

A You could use both connections to the TV, with the component video giving you the movie viewing image, and S-Video for when you want to see the on-screen display.

Q I just looked through your site for articles relating to 3:2 pulldown. I did not find any such articles. What I am looking for is a comprehensive coverage of 3:2 pulldown that encompasses the issue of having it available on the display device-[TV] itself as well as DVD players. Athough I would have an interest in 3:2 pulldown explained, it is really the issue of application to hardware availability that I am interested in at this point. What is behind this interest is that RPTVs that have 3:2 pulldown allow, as I understand it, for the proper presentation of any broadcast film content to be properly presented. Whenever I have asked this question of sales personal, they are relating it to DVD players with, and without this feature. While I understand the DVD issues, I would like to read more regarding the details regarding broadcast presentations. You are probably the best source of information regarding this question, so I look forward to hearing from you.

A I saw a salesperson at a store getting confused about this too. He mistook 3:2 pulldown for aspect ratio control. Most modern DVD players have 3:2 pulldown detection, which lets the player know when film-based sources vs. video-based sources are being played. (All DVD players have 16:9 vs. 4:3 presentation as well for that matter.) New digital TVs have 3:2 pulldown too, but usually, the pulldown is better in the DVD player. 3-2 pulldown is the ability to convert 24 fps sources into 60 fields per second video. We do mention these things in some of our articles, particularly Benchmark Part 5 and Shootout # 2. Remember that 16:9 presentation is different than aspect ratio control. Over 70% of the 16x9 TVs on the market today do not let you change aspect ratio when fed 480p. In these cases, you must watch all 4:3 and non-anamoprhic DVDs stretched.
 

Q I was in the process of buying a NAD T751 receiver. It has been recommended by a friend of mine due to its good inbuilt amplification and power resources plus I like the simplicity NAD builds into its products. But as regards to the rear connections, S-Video and Optical In, it can be said that they are a bit sparse, and the price compared to others is quite high (fewer features, DSPs etc.)!

How do you recommend this receiver, shall I go for it? Or do you think I must go for something else? It will be mainly used for Home Cinema, but will be used for music now and then. For your information my other
components are the following:

Sony Play Station 1
NAD T531 DVD Player
NAD T540 CD Player
Kef Coda 9.1 Front, Kef Coda 7SE Rear, Kef Cresta Centre Speaker
2 KODA SW800 Subs
Grundig Megatron 29 " TV 4:3

A NAD makes very nice products. We have tested some in the past and they do well. Features are easy to put into a product, but quality is not. That is why the NAD is more expensive than some other products. However, as long as it has at least one optical, one digital coaxial, and one S-Video, you should be fine. For DVD, go from the player direct to the TV. The S-Video connection on the receiver could be used with satellite TV. The two digital inputs could be used with two sources, one coaxial and one optical. However, if the receiver's optical and coaxial input are for a single source, that could be an issue unless you use your DVD player to handle CDs as well.

� Copyright 2002 Secrets of Home Theater & High Fidelity
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